Taoiseach Enda Kenny has said last week's fiscal treaty referendum result sends out a powerful message that Ireland is serious about overcoming its economic difficulties.

Mr Kenny said the passing of the treaty creates stability and certainty for foreign companies who invest in the country.

He was speaking at a conference on the subject of competitiveness in the Irish economy.

The event at Croke Park was hosted by US Ambassador Dan Rooney.

Speaking at the conference, President of Heinz William Johnson said Ireland continues to be an attractive place to do business.

He said Ireland has brought in investment by creating a business-friendly environment where companies are not burdened by excessive taxes that stifle competition, job creation and economic growth.

However, Mr Johnson also said it would be a concern if legislation is introduced in the US that would increase taxes on profits from the international operations of US-based companies.

He said more than 600 US companies are operating in Ireland, investing more than €190bn and employing more than 100,000 people.

Heinz employs 250 people at its plant in Dundalk, Co Louth.

Mr Kenny also said Ireland's 12.5 % corporation tax rate remains at the heart of the strategy to attract foreign direct investment.